Technical Field
The present disclosure relates generally to aerodynamic devices for use with trailers towed behind trucks. More particularly, the present disclosure relates to an air fairing and fender on a fluid tank trailer. Specifically, the present disclosure relates to an aerodynamic skirt beneath the trailer that smoothly transitions from the skirt beneath the trailer to the fender covering the wheels. The air fairing defining the skirt and fender may be one or more of the following: flexible, uniform, continuous, seamless, and uninterrupted.
Background Information
Trailers are pulled by road tractors/trucks. Typically these large devices are not very aerodynamic, and as such often create drag forces resulting in lessened gas mileage/fuel efficiency, amongst other things.
In an effort to increase efficiency, others have developed various aerodynamic skirts, air fairings, wind damns and the like. Ordinarily, the fairings include a planar segment extending beneath the trailer. Some trailer skirts for container trailers have been made flexible, as shown in U.S. Pat. No. 7,748,772. Furthermore, it is recognized that the shape of the skirts, and their respective positions on the road trailer, have a significant effect on the aerodynamic efficiency of the road trailer.
One example of an air fairing positioned beneath a platform box trailer is provided in U.S. Patent Application Publication No. 2017/0029044 (the '044 publication). The platform box trailer may also be referred to as a container trailer and the containing volume defined thereby is generally rectangular in cross section as shaped by the flat/planar wall of the trailer. The '044 publication indicates that its air fairing may include a front skirt fairing, a transition, and a rear skirt fairing. The transition may be angled slightly outward from the front skirt fairings but at no more than a twelve degree angle with respect to the center line of the cargo trailer. The angle of the transition provides clearance for the rear side skirt fairings to be located an additional three inches outward of the side of the forward side skirt fairings to accommodate trailer wheels on the back of the box trailer. As such, the linear path or a longitudinal plane along the length of the cargo trailer for rear side skirt fairings is located outwardly of the linear path or longitudinal plane of the forward side skirt fairings in order for it to clear the tires on the trailer wheels. The '044 publication indicates that Federal law allows the tires on the platform box trailer to exceed the outer base of the trailer envelope by three inches. As such, the '044 publication orients the transition of the rear side skirt fairings to allow the tires to reside within the three inch envelope to comply with Federal regulations. The front skirt fairing, the transition, and the rear skirt fairing of the '044 publication are fabricated from components constructing them in an interconnected manner. As such, each component is individually fabricated and then assembled to build the entire structure. Thus, there are seams between fairing segments and the entire design is not seamless, is not continuous, and not uniform.
Some trailers are referred to as tank trailers, which are different from the container trailer shown in U.S. Pat. No. 7,748,772 and the '044 publication. An exemplary tank trailer is shown in U.S. Pat. No. 8,845,008. Accordingly, since tank trailers are structurally different than the container trailer identified in U.S. Pat. No. 7,748,772 and the '044 publication, different structural requirements for air fairings, air deflectors, wind dams, or the like, are needed to reduce drag forces thereby increasing efficiency.